Can you think of any three-dimensional shape that comprises of exactly two surfaces?

What is the next number in this series?

4,12,84,3612....

John named his first son Alpha, second Beta, third Charlie and fourth Delta. What is the fifth son's name?

One night, a woman receives a call from the police. They tell her that her husband was murdered and that she should come to the crime scene as soon as possible. The woman drops the phone, shocked, and drives 20 minutes to the crime scene. As soon as she reaches the crime scene, the police arrest her and she is convicted of murder. How do the police know she committed the crime?

The person who makes it has no need for it. He who purchases it does not use it. The person who does use it does not know they are. What is it?

I am five letter word that is under you.
If you remove my 1st letter, then I am over you.
If you remove my 1st and 2nd letters then I am all around you.

Who am I?

If I put in one bird per cage, I have one bird too many. If I put in two bird per cage, I have one cage too many. How many cages and birds do I have?

If 21x = 79x, what is the value of x?

Can you find out what is missing?

1 3 5
2 4 ?

Hint: It's not six. Think out of the box.

What word is represented by this rebus?